Fuel transmission lines require pumping stations to transport the liquid or gaseous fuel across long distances. Because the fuel transmission lines are often in remote areas, the availability of electrical power to drive the pumps or the compressors is often limited or completely unavailable. Gas turbines generally are used in such remote areas while electric motors are preferred if a connection to an electrical grid is available.
As is well known, fuel cell systems can convert a fuel or gas stream into electrical power. Fuel cell systems have been considered for use with fuel transmission lines in the past. Known units included phosphoric fuel cells (PAFC) or molten carbonate fuel cells (MCFC) for supplying electricity for pipeline pumping for fuel or compression and co-generation for natural gas. Such known systems generally operated under high pressures and generally required the use of a turbocompressor. The net energy from these systems was DC power used for operating pumps or compressors. These known systems generally have limited efficiency.
There is a desire, therefore, for an improved fuel cell system that can be positioned at remote pumping stations along fuel transmission lines. The improved fuel cell system preferably can provide electrical power and/or mechanical force with improved efficiency while producing a limited amount of undesirable emissions.